{  Statement: http://acmp.ru/?main=task&id_task=324
   Verdict: Accepted
}
uses
    SysUtils, Math;

var
    i,ls,kk:longint;
    s:string;
    
begin
reset(input, 'input.txt');
rewrite(output, 'output.txt');
readln(s);
ls := length(s);
kk := ls shr 1;
for i := 1 to kk do
    if s[i] <> s[ls - i + 1] then begin
        write('NO');
        halt(0);
    end;
write('YES');
end.